The present invention relates to fasteners and more particularly to those fasteners which removably fasten two or more panels.
It is frequently desired, both in industrial and consumer products, to secure two or more panels. Many types of fasteners permit the panels to be separated and later refastened. However, although many types of fasteners have been commercially produced, and many more types have been proposed, for example, in the patent literature, there is a constant need for improved fasteners.
One general type of fastener comprises a stud member which fits into a socket member positioned in a hole in a panel. The stud member may be rotated to expand the socket outwardly and grip the edges or sidewall of the panel hole.
One fastener of this general type is shown in U.S. Pat. No. 1,300,580 to Carr, in which an expandable and contractible stud fits in a socket. The socket in one embodiment, may be expanded. In another embodiment the stud is locked in the socket by a cam turned by a handle (turn button) and the cam turns and expands the stud.
In U.S. Pat. No. 3,272,061 to Seckerson a stud is positioned in a tubular sleeve socket. The stud has lugs which bite into the sleeve when the stud is turned to expand the socket wall outwardly.
In U.S. Pat. No. 2,283,526 to Albin a stud (key member) carries a cross-pin (cross-bar) near its bottom edge. Upon rotation of the stud the cross-pin rides on spring loaded ramp members (cam or wedge members) and the cross-pin engages in a recess at the end of the ramp.
In the fasteners described in these patents the stud, upon its rotation, is neither moved along its axis nor applies equal outward cam action to a socket member.